Yes, No, and maybe!

Yes. This website and the project pages are still active. No, I don’t have an update on the VFO upgrade. Maybe this Summer, when I have some more time, I’ll get to posting the latest version I have been working on.

In the meantime… THANK YOU VERY MUCH to all who visit my site, try one of my projects, and send me a note about. I appreciate it.

Rich
AD7C

AD7C DDS VFO Update

More than two years ago I posted a project to this site detailing how I took a little DDS unit I found I eBay and controlled it with an Arduino UNO and LCD. The result was a very simple and stable VFO that just about anyone could build. It was also dirt cheap to replicate. I posted the code, put up some horrible schematics, and let it sit. I never thought much of it.

Little did I know that so many people would be interested in what I had created. I’ve been contacted by a lot of people, sent a lot of pictures of users units, helped a few people trouble shoot some issues, and even got published in a few books. What I do get the most is questions. A lot of questions. So to fix repeating myself a lot on emails here are some of the most popular email questions I get about the AD7C DDS VFO.

Q: Does it work?
A: Sure does. 200+ people have contacted me thanking me after they build the same project.

Q: I get an error on compiling. Something about “rotary.h not found?”
A: You did not import the rotary library correctly.

Q: Do I have to pay you if I build this?
A: No, but you can always donate to rvisokey@yahoo.com via PayPal if you wish. I’ll be extremely thankful!

Q: I wish it had THIS feature or THAT feature. Can you add that to the code and send it to me?
A: I could but what would be the fun in that? Learning coding is part of the fun so open up the Arduino code and give it a try yourself.

Q: Can I use any rotary encoder or does it have to be the same model you used?
A: So long as the rotary encoder outputs gray code you should be OK but I can’t guarantee that.

Hopefully that helps quickly answers some questions. I am working on a new version of the code. Nothing special but I am cleaning up a few sections. I don’t like that I have two versions of the code (IF and NON-IF version) so I am combining them into one and allowing a simple code change decide which way the user would like it to function. That and a few other improvements. I’ll post when I am done. Don’t worry… it will be 100% compatible with the existing schematic so no changes there.

Go melt some solder.

73,

Rich
AD7C

DSS VFO Update – Last Frequency Saved in EEPROM

I have updated the code to my Arduino DDS VFO sketch so the current set frequency is stored in EEPROM and recalled again upon boot-up. The code is 100% drop-in compatible with the old code and no re-wire is required. Simply upload the new sketch and your done. The frequency writes to the EEPROM after 3 seconds without changing. This was required so as not to overload the EEPROM as there are a finite amount of writes (100,000) before it may go bad. You can alter the delay time in my code as it is well documented.

View the entire project page for more details. If you have additional questions… just ask!

AD9850 Daughter Board for the Arduino by WB4CHK

A lot of people have been contacting me about my Arduino and AD9850 VFO project. I never knew DDS VFO’s were so popular! Go figure? Anyways… I digress!

A couple of days ago Dave (WB4CHK) contacted me with a few questions. He was on a quest to build a daughter-card that would plug in as a shield to the UNO. After a few back-and-forth items Dave finished his project. Rather than let me explain I’ll just post what he sent me below:

Hi Rich: I finished the Sig Gen board and it works great. The board plugs into the UNO, I hate batteries so I added a 5 volt regulated supply for the board and a 9 volt regulated supply for the UNO. Might be overkill but I can hook it up to my 12V+ bench supply and run all day. The outputs are the two 2pin connectors just below the 9850 module. The one on the right is sine wave the one on the left is connected to the square wave output (if it is ever added).

He also sent over a few photos of the finished unit. Pretty cool! Note: You won’t see the Arduino in any pics but it’s there. In fact, it’s underneath the board in the 3rd picture.
WB4CHK_AD9850_1
WB4CHK_AD9850_2
WB4CHK_AD9850_3

Dave has been so nice as to also provide the design and schematics he used to create his PCB. You can download the PCB design’s here. Using a laser printer and the toner-transfer method you should be able to duplicate Dave’s work. If you have any questions Dave gave me permission to post his email so go ahead and send him a note: Davewb4(at)aol.com. Obviously replace the (at) with the @ and you’re on your way.

InstaMorph Antenna Repair

I have been using a music stand to hold my SuperAntenna MP-1 for some time. With the music stand “tripod” base I get the antenna feed point up off the ground a few feet and also I end up with elevated radials. You can see the stand in use in this video at about the 4:30 mark.

I was never very happy about the down-and-dirty way I attached the antenna to the music stand.  I basically used an old CB style mount and just clamped it to the metal stand.  See the ugly mess below.SuperAntenna MP-1 Antenna MountAll week I kept trying to thinking of a better way to mount the 3/8×24 SO239 adapter to the music stand.  You notice above that I also have a wood stick between the mounting plate and the metal tube.  This keeps them electrically separate (non conductive).  I didn’t want the stand to be a part of the antenna counterpoise… or at least directly a part of it.  I had some great ideas but everything I came up with was just too complicated.

Tada!  I remembered my InstaMorph.  So a little hot water and a small handful of pellets turned into a just the mount I wanted.  Since I use this QRP and outdoors every ounce of weight reduction really helps.Picture 138You can see the size difference between the two.
SuperAntenna MP-1 Music MountI still have a couple more items to fabricate to finish the project but I like where it’s going.  I just need to drill another hold and use a screw to attach it to the music stand base.  Fairly simple.

If you haven’t tried InstaMorph you do a search on YouTube and check out all the great thing you can do with it.  I’m not involved with them in anyway but just love their product.